stop invoking `DebruijnIndex::new` directly

Co-authored-by: csmoe <35686186+csmoe@users.noreply.github.com>

8 files changed, 20 insertions, 21 deletions

diff --git a/src/librustc/infer/higher_ranked/mod.rs b/src/librustc/infer/higher_ranked/mod.rs
index 47fc8d96b55..cd73da9adc8 100644
--- a/src/librustc/infer/higher_ranked/mod.rs
+++ b/src/librustc/infer/higher_ranked/mod.rs
@@ -417,7 +417,8 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
         {
             for (a_br, a_r) in a_map {
                 if *a_r == r {
-                    return infcx.tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1), *a_br));
+                    return infcx.tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::INNERMOST,
+                                                               *a_br));
                 }
             }
             span_bug!(
diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index 37e8b1bae83..76a8db53a08 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -98,7 +98,7 @@ impl Region {
     }
 
     fn late(hir_map: &Map, def: &hir::LifetimeDef) -> (hir::LifetimeName, Region) {
-        let depth = ty::DebruijnIndex::new(1);
+        let depth = ty::DebruijnIndex::INNERMOST;
         let def_id = hir_map.local_def_id(def.lifetime.id);
         let origin = LifetimeDefOrigin::from_is_in_band(def.in_band);
         (def.lifetime.name, Region::LateBound(depth, def_id, origin))
@@ -107,7 +107,7 @@ impl Region {
     fn late_anon(index: &Cell<u32>) -> Region {
         let i = index.get();
         index.set(i + 1);
-        let depth = ty::DebruijnIndex::new(1);
+        let depth = ty::DebruijnIndex::INNERMOST;
         Region::LateBoundAnon(depth, i)
     }
 
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index 1582481120c..8e2c611d841 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -1024,7 +1024,7 @@ impl<'a, 'gcx, 'tcx> ParamTy {
 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug, Copy, PartialOrd, Ord)]
 pub struct DebruijnIndex {
     /// We maintain the invariant that this is never 0. So 1 indicates
-    /// the innermost binder. To ensure this, create with `DebruijnIndex::new`.
+    /// the innermost binder.
     pub depth: u32,
 }
 
@@ -1261,11 +1261,6 @@ impl<'a, 'tcx, 'gcx> PolyExistentialProjection<'tcx> {
 impl DebruijnIndex {
     pub const INNERMOST: DebruijnIndex = DebruijnIndex { depth: 1 };
 
-    pub fn new(depth: u32) -> DebruijnIndex {
-        assert!(depth > 0);
-        DebruijnIndex { depth: depth }
-    }
-
     /// Returns the resulting index when this value is moved into
     /// `amount` number of new binders. So e.g. if you had
     ///
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 9b7443f97ef..9ef3308efe6 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -555,7 +555,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                           -> Option<ty::Binder<Ty<'tcx>>>
     {
         let closure_ty = self.mk_closure(closure_def_id, closure_substs);
-        let env_region = ty::ReLateBound(ty::DebruijnIndex::new(1), ty::BrEnv);
+        let env_region = ty::ReLateBound(ty::DebruijnIndex::INNERMOST, ty::BrEnv);
         let closure_kind_ty = closure_substs.closure_kind_ty(closure_def_id, self);
         let closure_kind = closure_kind_ty.to_opt_closure_kind()?;
         let env_ty = match closure_kind {
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index 82afce415a7..4e7df0cac12 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -526,7 +526,7 @@ impl PrintContext {
                     ty::BrNamed(tcx.hir.local_def_id(CRATE_NODE_ID), name)
                 }
             };
-            tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1), br))
+            tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::INNERMOST, br))
         }).0;
         start_or_continue(f, "", "> ")?;
 
diff --git a/src/librustc_codegen_llvm/common.rs b/src/librustc_codegen_llvm/common.rs
index 6a4b87ced15..ab99d1f0f30 100644
--- a/src/librustc_codegen_llvm/common.rs
+++ b/src/librustc_codegen_llvm/common.rs
@@ -425,7 +425,7 @@ pub fn ty_fn_sig<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>,
             let tcx = cx.tcx;
             let sig = substs.poly_sig(def_id, cx.tcx);
 
-            let env_region = ty::ReLateBound(ty::DebruijnIndex::new(1), ty::BrEnv);
+            let env_region = ty::ReLateBound(ty::DebruijnIndex::INNERMOST, ty::BrEnv);
             let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty);
 
             sig.map_bound(|sig| {
diff --git a/src/librustc_driver/test.rs b/src/librustc_driver/test.rs
index 46f552ed28d..b22817a066c 100644
--- a/src/librustc_driver/test.rs
+++ b/src/librustc_driver/test.rs
@@ -183,6 +183,9 @@ fn test_env_with_pool<F>(
     });
 }
 
+const D1: ty::DebruijnIndex = ty::DebruijnIndex::INNERMOST;
+const D2: ty::DebruijnIndex = D1.shifted_in(1);
+
 impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
     pub fn tcx(&self) -> TyCtxt<'a, 'gcx, 'tcx> {
         self.infcx.tcx
@@ -332,7 +335,7 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
     }
 
     pub fn t_rptr_late_bound(&self, id: u32) -> Ty<'tcx> {
-        let r = self.re_late_bound_with_debruijn(id, ty::DebruijnIndex::new(1));
+        let r = self.re_late_bound_with_debruijn(id, D1);
         self.infcx.tcx.mk_imm_ref(r, self.tcx().types.isize)
     }
 
@@ -489,7 +492,7 @@ fn subst_ty_renumber_bound() {
 
         // t_expected = fn(&'a isize)
         let t_expected = {
-            let t_ptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, ty::DebruijnIndex::new(2));
+            let t_ptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, D2);
             env.t_fn(&[t_ptr_bound2], env.t_nil())
         };
 
@@ -526,7 +529,7 @@ fn subst_ty_renumber_some_bounds() {
         //
         // but not that the Debruijn index is different in the different cases.
         let t_expected = {
-            let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, ty::DebruijnIndex::new(2));
+            let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, D2);
             env.t_pair(t_rptr_bound1, env.t_fn(&[t_rptr_bound2], env.t_nil()))
         };
 
@@ -554,10 +557,10 @@ fn escaping() {
         let t_rptr_free1 = env.t_rptr_free(1);
         assert!(!t_rptr_free1.has_escaping_regions());
 
-        let t_rptr_bound1 = env.t_rptr_late_bound_with_debruijn(1, ty::DebruijnIndex::new(1));
+        let t_rptr_bound1 = env.t_rptr_late_bound_with_debruijn(1, D1);
         assert!(t_rptr_bound1.has_escaping_regions());
 
-        let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, ty::DebruijnIndex::new(2));
+        let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, D2);
         assert!(t_rptr_bound2.has_escaping_regions());
 
         // t_fn = fn(A)
@@ -573,7 +576,7 @@ fn escaping() {
 #[test]
 fn subst_region_renumber_region() {
     test_env(EMPTY_SOURCE_STR, errors(&[]), |env| {
-        let re_bound1 = env.re_late_bound_with_debruijn(1, ty::DebruijnIndex::new(1));
+        let re_bound1 = env.re_late_bound_with_debruijn(1, D1);
 
         // type t_source<'a> = fn(&'a isize)
         let t_source = {
@@ -588,7 +591,7 @@ fn subst_region_renumber_region() {
         //
         // but not that the Debruijn index is different in the different cases.
         let t_expected = {
-            let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, ty::DebruijnIndex::new(2));
+            let t_rptr_bound2 = env.t_rptr_late_bound_with_debruijn(1, D2);
             env.t_fn(&[t_rptr_bound2], env.t_nil())
         };
 
diff --git a/src/librustc_typeck/check/intrinsic.rs b/src/librustc_typeck/check/intrinsic.rs
index af1f1044edf..d894061c6ea 100644
--- a/src/librustc_typeck/check/intrinsic.rs
+++ b/src/librustc_typeck/check/intrinsic.rs
@@ -119,7 +119,7 @@ pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             "pref_align_of" | "min_align_of" => (1, Vec::new(), tcx.types.usize),
             "size_of_val" |  "min_align_of_val" => {
                 (1, vec![
-                    tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
+                    tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::INNERMOST,
                                                                   ty::BrAnon(0))),
                                     param(0))
                  ], tcx.types.usize)
@@ -298,7 +298,7 @@ pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             "unlikely" => (0, vec![tcx.types.bool], tcx.types.bool),
 
             "discriminant_value" => (1, vec![
-                    tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::new(1),
+                    tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::DebruijnIndex::INNERMOST,
                                                                   ty::BrAnon(0))),
                                    param(0))], tcx.types.u64),